In various forms of apparatus for treating of materials and particularly in crushers, mills and the like for crushing and grinding rocks and other hard and highly abrasive materials, difficulties have been encountered with respect to the support of elements which contact the material. The contact elements are subjected to wear and should, therefore, be replaceable. At the same time, they must be very firmly and reliably supported and the requirements are quite severe in many cases because of the impact forces applied to the elements during operation.
Various types of support arrangements have been used, generally including a bolt or other mechanically operable securing device. Such arrangements, while being generally satisfactory in operation have made it difficult and time-consuming to install the contact elements and they have not been without problems. In some cases, the elements have become detached from the supports which can cause serious problems in the operation of some types of material treating apparatus. There has also been a problem with loosening of the elements and some attempts have been made to use a rubber material which is compressed during assembly and designed to adjust for dimension changes from changes in temperature or otherwise.
Certain inherent problems have not been fully recognized and dealt with in the prior art. It has not been generally recognized that localized stress concentrations are frequently developed when using bolts or similar types of securing devices to cause problems with respect to failures and loosening of the supports. When rubber or rubber-like materials are used, they are apt to lose their resiliency and thus fail to perform their intended function because of being held in a severely stressed condition.